1. Field of the Inventions
These inventions relate to devices for raising a pressure of intake air for internal combustion engines, and more particularly, to a lubrication mechanisms for such devices.
2. Description of the Related Art
Superchargers, turbos, and other devices are used for supplying compressed air to the combustion chamber of engines to raise the power output of the engines. Superchargers typically include a rotor mounted on a shaft that is driven by the crankshaft of the associated engine. In some supercharger designs, the speed of the rotor relative to the crankshaft can be increased with a speed increasing mechanism.
In such a supercharger, lubricant oil can be supplied to the speed increasing mechanism to smooth its operation. Japanese Patent Document JP-B-3060489 discloses such a lubrication system for a supercharger. In this supercharger, lubricant oil is sealed in a housing accommodating the speed increasing mechanism. This speed increasing mechanism is a planetary roller type, including two (front and rear) stages.
In this system, a disk-shaped plate, which is a component of the rear one of the two-staged speed increasing mechanism, is provided with a first through hole bored along its axis and a second through hole is bored from the first through hole to the periphery of the plate. When the disk rotates, lubricant oil is urged into the first through hole and flows out of the second through hole by the rotation of the plate. Thus, the disk operates as a centrifugal pump and thereby supplies the oil to the planetary roller type speed increasing mechanism accommodated in the housing.